/*
 * $Header: /home/jerenkrantz/tmp/commons/commons-convert/cvs/home/cvs/jakarta-commons//httpclient/src/java/org/apache/commons/httpclient/methods/OptionsMethod.java,v 1.15 2004/04/18 23:51:37 jsdever Exp $
 * $Revision: 480424 $
 * $Date: 2006-11-29 06:56:49 +0100 (Wed, 29 Nov 2006) $
 *
 * ====================================================================
 *
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You under the Apache License, Version 2.0
 *  (the "License"); you may not use this file except in compliance with
 *  the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 *
 */

package org.apache.commons.httpclient.methods;

import org.apache.commons.httpclient.Header;
import org.apache.commons.httpclient.HttpConnection;
import org.apache.commons.httpclient.HttpMethodBase;
import org.apache.commons.httpclient.HttpState;

import org.apache.commons.logging.Log;
import java.util.Enumeration;
import java.util.StringTokenizer;
import java.util.Vector;

/**
 * Implements the HTTP OPTIONS method.
 * <p>
 * The HTTP OPTIONS method is defined in section 9.2 of <a
 * href="http://www.ietf.org/rfc/rfc2616.txt">RFC2616</a>: <blockquote> The
 * OPTIONS method represents a request for information about the communication
 * options available on the request/response chain identified by the
 * Request-URI. This method allows the client to determine the options and/or
 * requirements associated with a resource, or the capabilities of a server,
 * without implying a resource action or initiating a resource retrieval.
 * </blockquote>
 * </p>
 * 
 * @author <a href="mailto:remm@apache.org">Remy Maucherat</a>
 * @author <a href="mailto:mbowler@GargoyleSoftware.com">Mike Bowler</a>
 * @author <a href="mailto:jsdever@apache.org">Jeff Dever</a>
 * 
 * @version $Revision: 480424 $
 * @since 1.0
 */
public class OptionsMethod extends HttpMethodBase {

	// --------------------------------------------------------- Class Variables

	/** Log object for this class. */
	// private static final Log LOG = LogFactory.getLog(OptionsMethod.class);

	// ----------------------------------------------------------- Constructors

	/**
	 * Method constructor.
	 * 
	 * @since 1.0
	 */
	public OptionsMethod() {
	}

	/**
	 * Constructor specifying a URI.
	 * 
	 * @param uri
	 *            either an absolute or relative URI
	 * 
	 * @since 1.0
	 */
	public OptionsMethod(String uri) {
		super(uri);
	}

	// ----------------------------------------------------- Instance Variables

	/**
	 * Methods allowed.
	 */
	private Vector methodsAllowed = new Vector();

	// --------------------------------------------------------- Public Methods

	/**
	 * Get the name.
	 * 
	 * @return "OPTIONS"
	 * @since 2.0
	 */
	public String getName() {
		return "OPTIONS";
	}

	/**
	 * Is the specified method allowed ?
	 * 
	 * @param method
	 *            The method to check.
	 * @return true if the specified method is allowed.
	 * @since 1.0
	 */
	public boolean isAllowed(String method) {
		checkUsed();
		return methodsAllowed.contains(method);
	}

	/**
	 * Get a list of allowed methods.
	 * 
	 * @return An enumeration of all the allowed methods.
	 * 
	 * @since 1.0
	 */
	public Enumeration getAllowedMethods() {
		checkUsed();
		return methodsAllowed.elements();
	}

	// ----------------------------------------------------- HttpMethod Methods

	/**
	 * <p>
	 * This implementation will parse the <tt>Allow</tt> header to obtain the
	 * set of methods supported by the resource identified by the Request-URI.
	 * </p>
	 * 
	 * @param state
	 *            the {@link HttpState state} information associated with this
	 *            method
	 * @param conn
	 *            the {@link HttpConnection connection} used to execute this
	 *            HTTP method
	 * 
	 * @see #readResponse
	 * @see #readResponseHeaders
	 * @since 2.0
	 */
	protected void processResponseHeaders(HttpState state, HttpConnection conn) {
		// LOG.trace("enter OptionsMethod.processResponseHeaders(HttpState, HttpConnection)");

		Header allowHeader = getResponseHeader("allow");
		if (allowHeader != null) {
			String allowHeaderValue = allowHeader.getValue();
			StringTokenizer tokenizer = new StringTokenizer(allowHeaderValue,
					",");
			while (tokenizer.hasMoreElements()) {
				String methodAllowed = tokenizer.nextToken().trim()
						.toUpperCase();
				methodsAllowed.addElement(methodAllowed);
			}
		}
	}

	/**
	 * Return true if the method needs a content-length header in the request.
	 * 
	 * @return true if a content-length header will be expected by the server
	 * 
	 * @since 1.0
	 * 
	 * @deprecated only entity enclosing methods set content length header
	 */
	public boolean needContentLength() {
		return false;
	}

}
